An investigation of semantic patterns in passwords
Rafael Veras Guimarães · 2013
The advent of large password leaks in recent years has exposed the security problems of passwords and enabled deeper empirical investi-gation of password patterns. Researchers have only touched the sur-face of patterns in password creation, having characterized patterns in terms of frequency, length, composition rules and, to some extent, syn-tactic patterns. The semantics of passwords remain largely unexplored. In this thesis, we aim to fill this gap by employing Natural Language Processing techniques to extract and leverage understanding of seman-tic patterns in passwords. We present the first framework for segmenta-tion, semantic classification and semantic generalization of passwords and a model that captures the semantic essence of password samples. The results of our investigation demonstrate that the knowledge cap-tured by our model can be used to crack more passwords than the state-of-the-art approach. In experiments limited to 600 million guesses, our